Tampering with vessels or bottles containing pharmaceuticals or other liquids has been of major concern both to manufacturers and consumers. It will be appreciated that drugs in liquid form are most usually consumed by children, and that tampering with a bottle or container containing a drug for pediatric use creates such a problem for the manufacturer that any measure which is as effective as possible in alerting the user to potentially poisonous contamination is of paramount importance not only in saving the individual who uses the drug but also in preventing unwanted publicity for the manufacturer.
While, until the present, it has been mainly encapsulated drugs which have provided the focus for tampering efforts, with single-walled bottle construction, it is presently possible to penetrate the bottle with a syringe carrying, for instance, a poison, and then to reseal the bottle with a second syringe filled with a fast-setting adhesive. The result is that the liquid within the bottle is contaminated with the poison, with the ability to detect the violation of the bottle or container being almost impossible.
In the past there have been numerous systems for indicating the penetration or violation of packaged goods, some of which are illustrated in U.S. Pat. Nos. 4,436,203; 4,449,631; 4,295,566; 4,424,911; 4,434,893 and 4,457,430. All of the above-mentioned patents provide some measure of tamper indication. Some of the above-mentioned patents involve pressurized systems in which indicators are actuated via pressure or vacuum changes due to container penetration. Other of these patents describe systems in which tampering results in activation of a dye. In none of the above-mentioned patents is the concept of providing a mottled or spoiled appearance upon tampering either shown or taught. Rather, in some of the above patents, upon tampering either a complete color change of the package occurs, or the tampering results in the appearance of a printed warning.
By way of example, with prior pressure responsive systems, tampering can involve pressure changes which lead to indications that by and large are ignored by the buying public either out of ignorance or out of simple neglect. Also the shelf life of such products is limited due to the pressurization or vacuum involved. This is because plastic containers can typically only hold pressurization for six weeks to six months, whereas certain drugs in liquid form can stay on the pharmacist's shelf for as many as two or three years. Another reason for the lack of viability of such pressure-related indicators is that the buyer must be somewhat sophisticated to know what to look for in terms of either a pop-up cap or a change in the container configuration, which change may not be readily perceptible.
Moreover, the anti-tampering protection provided by pressurized bottles can be circumvented by the use of dry ice to evacuate the bottle slightly during the penetration attempt. Thus the pressurized anti-tampering devices can be easily circumvented.
With respect to dye-indication systems, those tampering indication methods in which a complete color change occurs are not sufficiently graphic to indicate tampering because the buyer is generally unfamiliar with what the container should look like as opposed to what it does look like after tampering. Moreover, for those materials which carry printed warnings in the form of inks which are activated upon tampering, it will be appreciated that such warnings are often ignored because the only evidence of tampering is additional printing. Moreover, most of these systems are activated by humidity in the air which takes a relatively long period of time. Additionally, when laminated layers are used, adhesive normally utilized to bond the multiple layers together restricts the flow of liquid to the dye-carrying layer such that even when water-sensitive dyes are utilized, either the dye is not activated because insufficient amount of water is in contact with the dye-carrying ink or because the aforementioned adhesive bonding prevents capillary action that would permit migration of the water to the dye. Additionally, carriers for imprinted inks prevent the bleeding of the dye away from its originally imprinted position. Thus these systems do not result in an indication of spoilage by dye bleeding. This is because water-activated print indicators are specifically designed not to bleed so that the information to be conveyed to the user will be clear and visible.
By way of further background, it should be noted that tamper-resistant containers have been provided with shrink-wrapped materials which in general may be easily removed and replaced without any visible indication that the particular container has been tampered with.